Probing Donor Acceptor Interactions of Chalcogenide Supported Fluorophosphonium Ions Using peri‐Substituted Acenaphthyl Scaffolds

The fluorination of the peri‐substituted acenaphthyl scaffolds 5‐PhE‐Ace‐6‐PPh2 (1E, E = O, S, Se, Te) using XeF2 afforded the difluorinated products 5‐PhE‐Ace‐6‐PF2Ph2 (2E, E = O, S, Se, Te) and tetrafluorinated products 5‐PhEF2‐Ace‐6‐PF2Ph2 (3E, E = Se, Te) depending on the stoichiometry applied. Fluoride abstraction of 2E using Me3SiOTf gave rise to the chalcogenide supported fluorophosphonium ions [5‐PhE‐Ace‐6‐P(F)Ph2](OTf) (4O and 5E, E = S, Se, Te). The molecular structure of 4O features a tetrahedral P atom, whereas those of the heavier analogs (5E, E = S, Se) contain trigonal bipyramidal P atoms that arise from intramolecular LP(E) → σ*(P–F) interactions.